In 2001, President George W. Bush issued an executive order banning federal funding for new sources of stem cells developed from preimplantation human embryos. The action stalled research and discouraged scientists. Five years later, a Kyoto University scientist, Shinya Yamanaka, and his graduate student, Kazutoshi Takahashi, re-energized the field by devising a technique to “reprogram” any adult cell

In 2001, President George W. Bush issued an executive order banning federal funding for new sources of stem cells developed from preimplantation human embryos. The action stalled research and discouraged scientists. Five years later, a Kyoto University scientist, Shinya Yamanaka, and his graduate student, Kazutoshi Takahashi, re-energized the field by devising a technique to “reprogram” any adult cell

Five years later, a Kyoto University scientist, Shinya Yamanaka, and his graduate student, Kazutoshi Takahashi, re-energized the field by devising a technique to “reprogram” any adult cell, such as a skin cell, and coax it back to its earliest “pluripotent” stage. From there it can become any type of cell, from a heart muscle cell to a neuron.

The breakthrough sidestepped the embryo controversy, offering researchers an unlimited supply of stem cells. Dr. Yamanaka shared the 2012 Nobel Prize in Physiology or Medicine for reprogramming mature cells into what are now called induced pluripotent stem cells, or iPS cells. Still, the march toward new treatments has been halting.

The International Society for Stem Cell Research (ISSCR), the world’s largest professional organization of stem cell scientists, today released newly updated guidelines for stem cell research and the development of new clinical therapies. Guidelines Update Steering Committee includes our Jeremy Sugarman

The International Society for Stem Cell Research (ISSCR), the world’s largest professional organization of stem cell scientists, today released newly updated guidelines for stem cell research and the development of new clinical therapies. Guidelines Update Steering Committee includes our Jeremy Sugarman

A tweak to a technique that edits DNA with pinpoint precision has boosted its ability to correct defective genes in people. Called CRISPR, the method is already used in the lab to insert and remove genome defects in animal embryos. But the genetic instructions for the machinery on which CRISPR relies — a gene-editing enzyme called Cas9 and RNA molecules that guide it to its target — are simply too large to be efficiently ferried into most of the human body’s cells.

This week, researchers report a possible way around that obstacle: a Cas9 enzyme that is encoded by a gene about three-quarters the size of the one currently used. The finding, published on 1 April in Nature, could open the door to new treatments for a host of genetic maladies (F. A. Ran et al. Nature http://dx.doi.org/10.1038/nature14299; 2015).